Thoughts on new amp

It is not necessarily just your amp but also likely your preamp. Do you know how much gain it has? Most preamps have way too much gain AFAIK. That's why I had mine built with only 10dB of gain, and actually could have gone as low as 6dB but at the time was askeered to go so low. Because of my low preamp gain I am able to get to satisfying output levels around the center travel of it's volume knob - the sweet (most linear) spot. You can likely get a preamp built with cutomized gain easier than an amp. Or perhaps insert attenuators?

I totally agree with Stevecham. If you don't think so, then look into a CJ tube power amp.

The phono stage has 48db gain, line stage = 31db

CJ 11/11a,PrimaLuna PL 5/7s,VAC kt-88.A 50-80W/ch tube amp should be enough.Auto-bias is usually a plus.

Too much gain for your loudspeaker/room is a common problem in component matching. I, and probably many others, have lived with a linestage volume range between 6 and 9:00 knowing it's not the optimal range for our linestages. In my current system I use a balanced linestage custom-built with internally switchable zero and +6dB gain, and still had to pull a voltage gain tube from my Atma Ma-1 amps to allow the linestage to run in its sweet spot. With so many high gain linestages and amps out there, excessive gain can require unconventional solutions. For me, reality is that my Atma MA-1 amps play with less distortion at say, 30 watt output than their smaller siblings, the M-60s do. So it's not as simple as substituting the less powerful amps and pocketing the cost difference. You may want to try a cheap used zero gain TVC or EVS/Endler resistor volume control in place of your preamp to determine how significant the voltage gain of your amp alone is in your system. You could keep the passive as a spare or sell for little penalty later.